1. Field of the Invention
The present invention relates to semiconductor devices and methods of manufacturing thereof. In particular, the invention relates to a semiconductor device having a capacitor and a method of manufacturing the semiconductor device.
2. Description of the Background Art
An analog or analogxe2x80xa2digital LSI (Large Scale Integration) such as analog/digital converter (A/D converter) and digital/analog converter (D/A converter) conventionally contains a capacitor (capacitive element) as a component of a filter circuit or an integrating circuit. FIG. 89 is a schematic cross section of a semiconductor device, conventional analogxe2x80xa2digital LSI and the like for example, showing a capacitor portion where a capacitor is formed and an interconnection portion where an interconnection is formed. FIG. 90 is a schematic cross section along line XCxe2x80x94XC in FIG. 89. A conventional semiconductor device is described below in conjunction with FIGS. 89 and 90.
Referring to FIGS. 89 and 90, an insulating film 102 is formed on a semiconductor substrate 101. A capacitor portion 120 includes one electrode 103a formed of a metal film that is deposited on insulating film 102. The other electrode 103b is formed to surround one electrode 103a with a space therebetween. An interlayer insulating film 108 is formed on one electrode 103a and the other electrode 103b. An interlayer insulating film part 108a is provided as a capacitor dielectric film between one electrode 103a and the other electrode 103b. The one electrode 103a, interlayer insulating film part 108a and the other electrode 103b constitute a capacitor.
A contact hole 110a formed in interlayer insulating film 108 is located in a region on one electrode 103a. A tungsten plug 111a fills the inside of contact hole 110a. An upper-level interconnection 112a is formed on tungsten plug 111a. Upper-level interconnection 112a is electrically connected to one electrode 103a via tungsten plug 111a. 
An interconnection portion 121 includes a first-level interconnection 103c formed on insulating film 102. The first-level interconnection 103c is constituted of a layer of the same level as that of one electrode 103a and the other electrode 103b. Interlayer insulating film 108 is deposited on the first-level interconnection 103c. A contact hole 110b is formed in interlayer insulating film 108 in a region on the first-level interconnection 103c. A tungsten plug 111b fills the inside of contact hole 110b. An upper-level interconnection 112b is formed on tungsten plug 111b. The upper-level interconnection 112b is electrically connected to the first-level interconnection 103c via tungsten plug 111b. 
The conventional semiconductor device as described above has a problem as discussed below. There is an increasing demand for scaling down and enhanced integration of semiconductor devices. The capacitor as shown in FIGS. 89 and 90 must secure a certain capacitance. In order to reduce the area occupied by the capacitor shown in FIGS. 89 and 90 while maintain a required capacitance, the thickness in the direction of height of one electrode 103a and the other electrode 103b can be increased to extend the surface area of sidewalls of one electrode 103a and the other electrode 103b serving as electrodes, or the distance between one electrode 103a and the other electrode 103b can be reduced.
However, when the thickness in the height direction of the one and the other electrodes 103a and 103b is increased, etching for fabricating the one and the other electrodes 103a and 103b is difficult. Therefore, this is not a realistic approach. On the other hand, when the distance between the one electrode 103a and the other electrode 103b is decreased, it would be difficult to reduce the distance smaller than the minimum process dimension of photolithography employed in a manufacturing process of the semiconductor device. Reduction of the area occupied by the capacitor is accordingly restricted.
It has been difficult for the conventional semiconductor device to secure a certain capacitance while reduce the area occupied by the capacitor as explained above.
One object of the present invention is to provide a semiconductor device having a capacitor enabling a certain capacitance to be secured and simultaneously allowing the size to be reduced, and to provide a method of manufacturing such a semiconductor device.
According to one aspect of the invention, a semiconductor device includes a capacitor lower electrode having an upper surface and including a metal film, a dielectric film deposited on the capacitor lower electrode and having its thickness smaller than that of the capacitor lower electrode, and a capacitor upper electrode deposited on the dielectric film, having its width smaller than that of the capacitor lower electrode and including a metal film.
The capacitor lower electrode, the dielectric film and the capacitor upper electrode are stacked in the vertical direction and accordingly a capacitor can be produced in the vertical direction. It is possible to control the thickness of the dielectric film such that the thickness is significantly smaller than the minimum process dimension of photolithography employed in fabrication of the semiconductor device. Then, with a certain capacitance secured, the thickness of the dielectric film can be made smaller than the conventional one to decrease the surface area of the capacitor upper and lower electrodes. As a result, the capacitor can be reduced in size compared with the conventional capacitor.
The width of the capacitor upper electrode is defined smaller than that of the capacitor lower electrode. It is then possible to obtain an increased alignment margin for photolithography by which the capacitor upper electrode is formed. Occurrence of defect can be avoided, such as short-circuit between the sidewall for example of the capacitor lower electrode and the capacitor upper electrode due to misalignment of the capacitor upper and lower electrodes.
As the capacitor upper and lower electrodes include metal films, a capacitor (capacitive element) can be implemented having a higher precision and less voltage-dependency, compared with a semiconductor device employing semiconductor like polysilicon as a capacitor electrode. A capacitor necessary for a high-precision filter circuit or the like can readily be achieved in this way.
For the semiconductor device according to the one aspect, the capacitor upper electrode may have a sidewall, and the semiconductor device may include a sidewall insulating film formed on the upper surface of the capacitor lower electrode and on the sidewall of the capacitor upper electrode.
The sidewall insulating film provided between the sidewall of the capacitor upper electrode and the upper surface of the capacitor lower electrode can surely prevent short-circuit between the capacitor upper electrode and the capacitor lower electrode.
Further, as discussed later regarding a manufacturing process, the capacitor upper electrode and the sidewall insulating film can be utilized as a mask in etching for fabricating the capacitor lower electrode. Accordingly, the capacitor lower electrode located under the capacitor upper electrode and having its width greater than that of the capacitor upper electrode can surely be formed.
For the semiconductor device according to the one aspect, the sidewall insulating film preferably includes a silicon oxynitride film.
The silicon oxynitride film functions as an ARC (Anti Reflection Coat). A separate ARC is thus made unnecessary by forming the silicon oxynitride film constituting the sidewall insulating film from a region on the capacitor upper electrode to another region and forming on this silicon oxynitride film a photoresist film employed in etching for forming an interconnection or the like on that another region. The manufacturing process can thus be simplified.
For the semiconductor device according to the one aspect, the capacitor lower electrode may include aluminum and the capacitor upper electrode may include tungsten.
When the capacitor lower electrode and the capacitor upper electrode are formed of respective materials different from each other, the capacitor upper electrode can surely be used as a mask in etching for producing the capacitor lower electrode. Misalignment between the capacitor upper and lower electrodes can thus be prevented.
The semiconductor device according to the one aspect may further include a lower interconnection portion constituted of a layer at the same level as that of the capacitor lower electrode, another dielectric film deposited on the lower interconnection portion, an upper interconnection portion deposited on that another dielectric film, having its width smaller than that of the lower interconnection portion and constituted of a layer at the same level as that of the capacitor upper electrode, and an interlayer insulating film formed on the upper interconnection portion. In the interlayer insulating film, a connection hole may be formed that exposes a surface of the upper interconnection portion and reaches the upper surface of the lower interconnection portion. The semiconductor device according to the one aspect may further include a conductive film provided inside the connection hole to electrically connect the upper and lower interconnection portions.
In the process of fabricating the capacitor formed of the capacitor lower electrode, the dielectric film and the capacitor upper electrode, an interconnection can simultaneously be fabricated that is formed of the upper and lower interconnection portions. The upper and lower interconnection portions can serve as one interconnection if the conductive film is used to electrically connect these interconnection portions.
According to another aspect of the invention, a semiconductor device includes a capacitor lower electrode having an upper surface and a sidewall surface and including a metal film, a dielectric film deposited on the capacitor lower electrode to extend from the upper surface to the sidewall surface and having its thickness smaller than that of the capacitor lower electrode, and a capacitor upper electrode deposited on the dielectric film and including a metal film.
The capacitor lower electrode, the dielectric film and the capacitor upper electrode are stacked in the vertical direction and accordingly a capacitor can be produced in the vertical direction. It is possible to control the thickness of the dielectric film such that the thickness is significantly smaller than the minimum process dimension of photolithography employed in fabrication of the semiconductor device. Then, even if the thickness of the dielectric film is made smaller than a conventional one in order to reduce the surface area of the capacitor upper and lower electrodes, a certain capacitance can be secured. The capacitor can thus be reduced in size compared with the conventional capacitor.
The dielectric film is deposited on the capacitor lower electrode to extend from the upper surface to the sidewall surface of the lower electrode. Therefore, even if the position of the capacitor upper electrode shifts and accordingly the capacitor upper electrode extends onto the sidewall surface of the capacitor lower electrode, the dielectric film is present between the capacitor upper and lower electrodes. Prevention is surely possible of short-circuit between the capacitor upper and lower electrodes in this way.
As the capacitor upper and lower electrodes include metal films, a capacitor (capacitive element) can be implemented having a higher precision and less voltage-dependency, compared with a semiconductor device employing semiconductor like polysilicon as a capacitor electrode. A capacitor necessary for a high-precision filter circuit or the like can readily be achieved in this way.
For the semiconductor device according to that another aspect, the capacitor upper electrode may have its width smaller than that of the capacitor lower electrode.
It is then possible to obtain an increased alignment margin for photolithography by which the capacitor upper electrode is formed. Occurrence of defect can be avoided, such as short-circuit between the sidewall for example of the capacitor lower electrode and the capacitor upper electrode due to misalignment of the capacitor upper and lower electrodes.
For the semiconductor device according to that another aspect, the capacitor upper electrode may have its width greater than that of the capacitor lower electrode.
In this case, the capacitor upper electrode is located on the sidewall of the capacitor lower electrode with the dielectric film therebetween. Consequently, the sidewall of the capacitor lower electrode can be utilized as a capacitor electrode, which can increase the capacitance of the capacitor.
According to still another aspect of the invention, a semiconductor device includes an interlayer insulating film having a trench, a capacitor lower electrode filling the inside of the trench and including a metal film, a dielectric film deposited on the capacitor lower electrode and having its thickness smaller than that of the interlayer insulating film, and a capacitor upper electrode deposited on the dielectric film and including a metal film.
The capacitor lower electrode, the dielectric film and the capacitor upper electrode are stacked in the vertical direction and accordingly a capacitor can be produced in the vertical direction. It is possible to control the thickness of the dielectric film such that the thickness is significantly smaller than the minimum process dimension of photolithography employed in fabrication of the semiconductor device. Then, with a certain capacitance secured, the thickness of the dielectric film can be made smaller than the conventional one to decrease the surface area of the capacitor upper and lower electrodes. As a result, the capacitor can be reduced in size compared with the conventional capacitor.
The capacitor lower electrode has a so-called damascene structure that fills the inside of the trench of the interlayer insulating film. When a semiconductor device employs a damascene interconnection as one interconnection, this interconnection can partially be used as a capacitor lower electrode. Then, a capacitor of vertical type can readily be implemented in the semiconductor device having such a damascene interconnection.
As the capacitor upper and lower electrodes include metal films, a capacitor (capacitive element) can be implemented having a higher precision and less voltage-dependency, compared with a semiconductor device employing semiconductor like polysilicon as a capacitor electrode. A capacitor necessary for a high-precision filter circuit or the like can readily be achieved in this way.
According to a further aspect of the invention, a semiconductor device includes one capacitor electrode including a first extension and a second extension horizontally spaced apart from the first extension, and the other capacitor electrode including a third extension located between the first extension and the second extension, opposed to the first extension with a dielectric film therebetween and opposed to the second extension with a dielectric film therebetween and including a fourth extension opposed to the second extension with a dielectric film therebetween that is different from the dielectric film between the second and third extensions, the third and fourth extensions located on different sides of the second extension.
When the first and second extensions and the third and fourth extensions are alternately arranged in this way, the one and the other capacitor electrodes accordingly have the first to fourth extensions with their sidewall surfaces opposing each other that can be utilized as an electrode surface of the capacitor. Specifically, almost all the sidewall surfaces of the second and third extensions can be used as a capacitor electrode surface. In the case of the conventional capacitor shown in FIGS. 89 and 90, the other electrode is arranged to surround the one electrode so that the outer sidewall surface that is not opposite to the one electrode does not function as a capacitor electrode surface. On the other hand, the capacitor of the present invention has the first extension of the one electrode formed so as to enable the outer sidewall surface of the other electrode (the sidewall surface of the third extension opposing the first extension) to be utilized as a capacitor electrode. The volume of a region occupied by the capacitor is then smaller than occupied by a plurality of such conventional capacitors one of which as shown in FIGS. 89 and 90 provided for securing a certain capacitance. Further, the capacitance of the capacitor can readily be changed since the area of the capacitor electrode surface can easily be varied.
According to a still further aspect of the invention, a semiconductor device includes an interlayer insulating film having a plurality of holes, a plurality of capacitor lower electrodes provided inside the holes of the interlayer insulating film and including a metal film, a dielectric film deposited on the capacitor lower electrodes, and a capacitor upper electrode deposited on the dielectric film and including a metal film.
The capacitor lower electrode, the dielectric film and the capacitor upper electrode are stacked in the vertical direction and accordingly a capacitor can be produced in the vertical direction. It is possible to control the thickness of the dielectric film such that the thickness is significantly smaller than the minimum process dimension of photolithography employed in fabrication of the semiconductor device. Then, with a certain capacitance secured, the thickness of the dielectric film can be made smaller than the conventional one to decrease the surface area of the capacitor upper and lower electrodes. As a result, the capacitor can be reduced in size compared with the conventional capacitor.
The number as well as the cross sectional area of the holes formed in the interlayer insulating film can be changed to facilitate change of the area of the region of the capacitor lower electrodes that is opposite to the dielectric film. As a result, the capacitance of the capacitor can easily be changed.
As the capacitor upper and lower electrodes include metal films, a capacitor (capacitive element) can be implemented having a higher precision and less voltage-dependency, compared with a semiconductor device employing semiconductor like polysilicon as a capacitor electrode. A capacitor necessary for a high-precision filter circuit or the like can readily be achieved in this way.
According to a still further aspect of the invention, a semiconductor device includes a capacitor lower electrode including a metal film, a dielectric film deposited on the capacitor lower electrode and having its thickness smaller than that of the capacitor lower electrode, an interlayer insulating film deposited on the dielectric film and having an opening that exposes the dielectric film, and a capacitor upper electrode provided inside the opening and including a metal film.
The capacitor lower electrode, the dielectric film and the capacitor upper electrode are stacked in the vertical direction and accordingly a capacitor can be produced in the vertical direction. It is possible to control the thickness of the dielectric film such that the thickness is significantly smaller than the minimum process dimension of photolithography employed in fabrication of the semiconductor device. Then, with a certain capacitance secured, the thickness of the dielectric film can be made smaller than the conventional one to decrease the surface area of the capacitor upper and lower electrodes. As a result, the capacitor can be reduced in size compared with the conventional capacitor.
Further, as the capacitor upper electrode is placed inside the opening, the conventionally required process of forming a contact hole for connecting the capacitor upper electrode and an upper-level interconnection after formation of the capacitor upper electrode is unnecessary. The manufacturing process of a semiconductor device can thus be simplified.
As the capacitor upper and lower electrodes include metal films, a capacitor (capacitive element) can be implemented having a higher precision and less voltage-dependency, compared with a semiconductor device employing semiconductor like polysilicon as a capacitor electrode. A capacitor necessary for a high-precision filter circuit or the like can readily be achieved in this way.
For the semiconductor device according to the one aspect, another aspect, still another aspect, further aspect or still further aspects of the invention, the capacitor formed of the capacitor upper electrode, the dielectric film and the capacitor lower electrode is preferably employed in an application specific integrated circuit.
The application specific integrated circuit (ASIC) requires a capacitor to be implemented that has a high precision and no voltage-dependency and can easily be reduced in size. The present invention would be remarkably advantageous, if applied to the ASIC, in enhancement of the performance and scaling down of the ASIC.
According to a still further aspect of the invention, a method of manufacturing a semiconductor device includes the steps of forming a capacitor lower electrode having an upper surface, forming a dielectric film on the upper surface of the capacitor lower electrode, the dielectric film having its thickness smaller than that of the capacitor lower electrode, forming a metal film on the dielectric film, forming a resist film on the metal film, the resist film having its width smaller than that of the capacitor lower electrode, and forming a capacitor upper electrode by partially removing the metal film by means of etching using the resist film as a mask, the capacitor upper electrode having its width smaller than that of the capacitor lower electrode.
In this way, a capacitor in the vertical direction can readily be produced that is constituted of the capacitor lower electrode, the dielectric film and the capacitor upper electrode stacked in the vertical direction.
The resist film used for forming the capacitor upper electrode has its width defined smaller than that of the capacitor lower electrode. Then, an increased alignment margin between the resist film and the capacitor lower electrode can be obtained in a photolithography process for forming the resist film. Accordingly, it is possible to prevent occurrence of defect, such as short-circuit between the sidewall surface for example and the capacitor upper electrode due to misalignment of the capacitor upper and lower electrodes.
According to a still further aspect of the invention, a method of manufacturing a semiconductor device includes the steps of forming a capacitor lower electrode having an upper surface and a sidewall surface, forming a dielectric film deposited on the capacitor lower electrode and extending from the upper surface to the sidewall surface, the dielectric film having its thickness smaller than that of the capacitor lower electrode, forming a metal film on the dielectric film, forming a resist film on the metal film, and forming a capacitor upper electrode by partially removing the metal film by means of etching using the resist film as a mask.
In this way, a capacitor in the vertical direction can readily be produced that is constituted of the capacitor lower electrode, the dielectric film and the capacitor upper electrode stacked in the vertical direction.
The dielectric film extends from the upper surface to the sidewall surface of the capacitor lower electrode. Therefore, when the position of the resist film for forming the capacitor upper electrode shifts and accordingly the capacitor upper electrode extends onto the sidewall surface of the capacitor lower electrode, the dielectric film is present between the capacitor upper electrode and the sidewall of the capacitor lower electrode. It is thus possible to surely prevent short-circuit between the upper and lower electrodes.
Regarding the method of manufacturing a semiconductor device according to the still further aspect of the invention, the step of forming a resist film may include the step of forming a resist film having its width smaller than that of the capacitor lower electrode.
An increased alignment margin is thus secured between the resist film and the capacitor lower electrode in a photolithography process for forming the resist film.
Regarding the method of manufacturing a semiconductor device according to the still further aspect of the invention, the step of forming a resist film may include the step of forming a resist film having its width greater than that of the capacitor lower electrode.
Accordingly, the capacitor upper electrode deposited on the capacitor lower electrode extends from the upper surface to the sidewall surface of the capacitor lower electrode with the dielectric film therebetween. The sidewall surface of the capacitor lower electrode can thus be utilized as a capacitor electrode. An increased capacitance of the capacitor can be achieved in this way.
According to a still further aspect of the invention, a method of manufacturing a semiconductor device includes the steps of forming a lower metal film constituting a capacitor lower electrode, forming a dielectric film on the lower metal film, forming a capacitor upper electrode deposited on the dielectric film and including a metal film, and forming the capacitor lower electrode by partially removing the lower metal film through etching using the capacitor upper electrode as a mask.
In this way, a capacitor in the vertical direction can readily be produced that is constituted of the capacitor lower electrode, the dielectric film and the capacitor upper electrode stacked in the vertical direction.
As the capacitor lower electrode is formed by using the capacitor upper electrode as a mask, misalignment of the capacitor upper and lower electrodes can surely be avoided.
Regarding the method of manufacturing a semiconductor device according to the still further aspect of the invention, in the step of forming the dielectric film, the dielectric film may be formed to extend to a region where an interconnection is formed by using the lower metal film. Further, the method of manufacturing a semiconductor device according to the still further aspect of the invention may further include the step, preceding the step of forming the capacitor lower electrode, of forming a resist film on the dielectric film on the region where an interconnection is formed by using the lower metal film, and forming the interconnection by partially removing the lower metal film by using the resist film as a mask.
In this case, when a material functioning as an ARC (anti reflection coat) is employed as the dielectric film, the step of separately forming an ARC for the resist film formed on the dielectric film is unnecessary. A simpler manufacturing process of the semiconductor device can thus be accomplished.
Regarding the method of manufacturing a semiconductor device according to the still further aspect of the invention, preferably the dielectric film includes a silicon oxynitride film.
The silicon oxynitride film functions as an ARC. Then, the silicon oxynitride film can be used as the capacitor dielectric film to allow the capacitor dielectric film to function as an ARC in an easy manner.
The method of manufacturing a semiconductor device according to the still further aspect of the invention may further include the step, preceding the step of forming the capacitor lower electrode, forming a sidewall film on a sidewall surface of the capacitor upper electrode, and, in the step of forming the capacitor lower electrode, the capacitor upper electrode and the sidewall film may be used as a mask.
The capacitor upper electrode and the sidewall film are utilized as a mask in etching for fabricating the capacitor lower electrode. Then, the capacitor lower electrode located under the capacitor upper electrode and having its width greater than the capacitor upper electrode can surely be produced.
The method of manufacturing a semiconductor device according to the still further aspect of the invention may further include the step, preceding the step of forming the capacitor lower electrode, forming an upper interconnection portion deposited on the dielectric film, having a sidewall surface and constituting an interconnection layer, and may further include the steps of forming an interconnection sidewall film on the sidewall surface of the upper interconnection portion, forming a lower interconnection portion by partially removing the lower metal film through etching using the interconnection sidewall film and the upper interconnection portion as a mask, forming an interlayer insulating film on the upper interconnection portion, forming a connection hole in the interlayer insulating film, the connection hole exposing a surface of the upper interconnection portion and reaching an upper surface of the lower interconnection portion, and forming a conductive film in the connection hole that is electrically connected to the upper and lower interconnection portions.
In the step of fabricating a capacitor formed of the capacitor lower electrode, the dielectric film and the capacitor upper electrode, an interconnection constituted of the upper and lower interconnection portions can simultaneously be produced.
According to a still further aspect of the invention, a method of manufacturing a semiconductor device includes the steps of preparing an interlayer insulating film, forming a trench in the interlayer insulating film, forming a capacitor lower electrode filling the trench and including a metal film, forming a dielectric film deposited on the capacitor lower electrode and having its thickness smaller than that of the interlayer insulating film, and forming a capacitor upper electrode deposited on the dielectric film and including a metal film.
In this way, a capacitor in the vertical direction can be produced that is constituted of the capacitor lower electrode, the dielectric film and the capacitor upper electrode stacked in the vertical direction.
The capacitor lower electrode has a so-called damascene structure that fills the inside of the trench of the interlayer insulating film. When a semiconductor device employs a damascene interconnection as one interconnection, a part of this interconnection can easily be used as a capacitor lower electrode.
According to a still further aspect of the invention, a method of manufacturing a semiconductor device includes the steps of forming a metal film, forming a resist film on the metal film, and forming, by partially removing the metal film using the resist film as a mask, one capacitor electrode including a first extension and a second extension horizontally spaced apart from the first extension and the other capacitor electrode including a third extension located between the first extension and the second extension, opposed to the first extension with a dielectric film therebetween and opposed to the second extension with a dielectric film therebetween and including a fourth extension opposed to the second extension with a dielectric film therebetween that is different from the dielectric film between the second and third extensions, the third and fourth extensions located on different sides of the second extension.
In this way, a capacitor can readily be produced including the one and the other capacitor electrodes with the first to fourth extensions having sidewall surfaces opposing each other that can be utilized as a capacitor electrode surface.
According to a still further aspect of the invention, a method of manufacturing a semiconductor device includes the steps of preparing an interlayer insulating film, forming a plurality of holes in the interlayer insulating film, forming a metal film extending from the inside of the holes onto an upper surface of the interlayer insulating film, forming a plurality of capacitor lower electrodes provided in the holes and including a metal film by removing a part of the metal film located on the upper surface of the interlayer insulating film and forming a depression in the upper surface of the interlayer insulating film in a region where the holes are provided, filling the depression with a dielectric film, and forming a capacitor upper electrode including a metal film on the dielectric film.
In this way, a capacitor in the vertical direction can readily be produced that is constituted of the capacitor lower electrode, the dielectric film and the capacitor upper electrode stacked in the vertical direction.
In the step of forming a plurality of holes in the interlayer insulating film, the number and the cross sectional area of the holes can be changed to easily change the area of a region of the capacitor lower electrode, that is opposite to the dielectric film. The capacitance of the capacitor can thus be changed by an easy way.
According to a still further aspect of the invention, a method of manufacturing a semiconductor device includes the steps of forming a capacitor lower electrode including a metal film, forming a dielectric film deposited on the capacitor lower electrode and having its thickness smaller than that of the capacitor lower electrode, forming an interlayer insulating film on the dielectric film, forming an opening in the interlayer insulating film in a region located on the dielectric film so as to expose the dielectric film, and forming a capacitor upper electrode provided in the opening and including a metal film.
In this way, a capacitor in the vertical direction can readily be produced that is constituted of the capacitor lower electrode, the dielectric film and the capacitor upper electrode stacked in the vertical direction.
The capacitor upper electrode is provided in the opening. Therefore, the step of forming a contact hole, after the step of forming the capacitor upper electrode, for connecting the capacitor upper electrode and an upper-level interconnection is unnecessary which has been required for the conventional semiconductor device.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.